In various circumstances it is desirable to know the relative velocity between a surface and an object. It is especially desirable in some applications to be able to determine the relative velocity between a surface and an object without physical contact between the surface and the object.
A prior art technique for determining the relative velocity between a surface and a velocity determination system involves capturing frames of digital image information with an image sensor and then performing a cross-correlation to identify the relative movement of an image feature that is captured in both image frames. The relative movement of an image feature can then be used in combination with the elapsed time between frame capture to determine relative velocity. Although this technique works well, the capturing of frames of digital image information and the cross-correlation of image features are both resource intensive operations.